Conventionally-used black-and-white photographic materials (for X-rays, plate making and microcopies) are developed in a short period of time of from one to five minutes by using automatic processors. However, photographic processors wish to complete processing even faster to accommodate the increase in photographs being taken. Also, photographic materials like those used for X-rays must be processed as soon as possible to provide important information in a timely manner. Under these circumstances, the time taken for the development of photographic materials is being decreased from a period of more than one minute to a period of one minute or less.
In addition, medical photographic materials giving X-ray photographic images of high quality are required for improving diagnostic accuracy. Also, photographic materials for plate making are repeatedly subjected to processing stages. However, when the photographic materials do not have sufficient resolving power, the image fades every time the materials are processed. For this reason, photographic materials giving images of high quality are being demanded.
Further, photographic materials for plate making are often being exposed to laser beams. They must provide images of high quality even under high illumination. In microcopies, photographed images are not directly observed; instead, enlarged photographs are observed, and images of high quality are demanded.
Thus, it should be understood that rapid processing in a period of time of not longer than 60 seconds and images of high quality being required.
Attempts have been made to provide photographic materials giving images of good quality. For example, photographic emulsion layers or other layers have been colored to absorb light having a specific wavelength. A colored layer has been provided between a photographic emulsion layer and a support or on the side opposed to the emulsion layer-side of the support for the purpose of preventing image from being faded by the fact that incident light is reflected during the passage thereof through the photographic emulsion layers, or transmitted light is scattered and reflected at the interface between the emulsion layer and the support or on the surface of the side opposed to the emulsion layer-side of the support, and reflected light enters again the photographic emulsions, that is, for the purpose of antihalation. The colored layer is called antihalation layer (AH layer). In the photographic materials for X-ray photographs, a colored layer is sometimes provided as a crossover cut layer for reducing crossover light to improve sharpness.
These colored layers often comprise hydrophilic colloid. Hence, dyes are generally incorporated in these layers to color them. The dyes must meet the following requirements.
(1) The dyes must have proper spectral absorption according to the purposes of their use.
(2) The dyes must be chemically inactive in regard to the photographic material. Namely, they can not chemically have an adverse effects on the performance of photographic silver halide emulsion layers. For example, they cannot cause a lowering of sensitivity, latent image fading or fogging.
(3) The dyes must be either decolorized, or dissolved and removed during the course of development to prevent harmful after-color from being left on the photographic materials after processing.
Methods for providing dye-containing layers include a method wherein soluble dyes are dissolved in hydrophilic colloid layers as disclosed in U.K. Patents 1,414,456, 1,477,638 and 1,477,639. This method has the disadvantage in that when the solubility of the dyes in water is increased to solve the problem of after-color, the fixing degree of the dyes are reduced, the dyes are diffused in layers adjacent to the dye-containing layer and desensitization or the re-transfer of the dyes to other photographic materials result. Methods wherein hydrophilic polymers having an electric charge opposite to dissociated anionic dyes are allowed to coexist as mordants in a layer to thereby localize the dyes in a specific layer by the interaction between dye molecules and polymers, are described in U.S. Pat. Nos. 2,548,564, 4,124,386 and 3,625,694. However, these methods have the disadvantages in that when anionic substances and dyes exist in the same layer, an undesirable effect on the manufacturing process results so that the dyes are not satisfactorily localized and the coating solutions cause agglomeration.
To solve these problems, a method has been proposed wherein dyes dispersed in the form of solid particle are allowed to exist between the support and the emulsion layer as disclosed in U.S. Pat. No. 4,803,150 and WO 88/04794. This method is an excellent technique for providing an image of high quality without causing desensitization.
However, this method has problems in the production of the photographic materials and the rapid processing in a period of time of not longer than 60 seconds. First, the problem of rapid processing will be discussed. When an additional layer is provided as an AH layer, the total amount of hydrophilic colloid is increased, because the AH layer generally comprises hydrophilic colloid. When the amount of hydrophilic colloid increases, the amount of water absorbed by the photographic material in the processing stage increases and drying is adversely affected. This is a serious problem for rapid processing in a period of time of not longer than 60 seconds. Also, the amount of hypo (sodium thiosulfate) left in the photographic materials for X-ray photographs and microcopies after development must be small, because the photographic materials are stored over a long period of time. When the amount of hydrophilic colloid is large, the amount of hypo absorbed in fixing solutions increases, and the rinsing time must be prolonged to wash the hypo off. This is a serious problem for rapid processing. In regard to the problem in the production of the photographic materials, the extra layer complicates the production process and tends to cause surface troubles.